January 2001 doc.: IEEE 802.11-01/057-r1
January 2001 doc.: IEEE 802.15-01/035-r1
IEEE P802.11/15
Regulatory
IEEE 802.11/15 ad-hoc regulatory
Date:January 16, 2001
Author:Peter Murray, Intersil Corporation.
Phone: 908-232-9054
e-Mail:
This document is a position paper from the following working groups of the IEEE Project 802, the Local and Metropolitan Network Standards Committee:
[IEEE Working Group 802.11 for Wireless Local Area Networks, and]
[IEEE Working Group 802.15 for Wireless Personal Area Networks.]
Abstract
This draft recommendation provides updated information of the IEEE 802.11a and ETSI BRAN Hiperlan2 technical parameters including multiple access and modulation schemes.
The document is for informational purposes to assist other standard and regulatory bodies in studies and calculations for band sharing and interference avoidance with primary users of the 5 GHz band.
Further updates to the draft will be made from time to time as more information becomes available.
Source:Document 8A/10(Rev.1) Peter Murray, Intersil
Working Party 8A
Proposed update To
Draft new Recommendation ITU-R M.[8A9B-T4/DD][*],[**]
characteristics of broadband radio local area networks (rlans)
(Questions ITU-R 212/8 and ITU-R 142/9)
Summary
This Recommendation provides preferred technical parameters including multiple access and modulation schemes, as well as general guidance for system design of broadband RLANs for mobile applications. Some of them are still under study and will be incorporated in lLater revisions may be necessary as the technology evolves. The term "broadband" RLAN in this Recommendation means a transmission capacity higher than the order of 10Mbit/s.
The ITU Radiocommunication Assembly,
considering
a)that broadband RLANs will be widely used for semi-fixed (transportable) and portable computer equipment for a variety of broadband applications;
b)that broadband RLAN standards currently being developed will be compatible with current wired LAN standards;
c)that it is desirable to establish guidelines for broadband RLANs in various frequency bands;
d)that broadband RLANs should be implemented with careful consideration to compatibility with other radio applications;
e)that the above guidelines should not limit the effectiveness of broadband RLANs but be used to enhance their development,
recommends
1that for guidance on preferred methods of multiple access and modulation techniques for broadband RLANs in mobile applications Table 2 can be referred to;
2that for guidance on existing broadband RLAN standardsapplications currently under development, Table 3 can be referred to;
3that for guidance on the characteristics of broadband RLANs, Annex 1 can be referred to;
4that for guidance on modulation schemes using OFDM for broadband RLANs, Annex 2 can be referred to;
5that for detailed guidance on remote access schemes for RLANs in mobile applications Annex 3 can be referred to;
6that for other information on RLANs Recommendation refer to Recommendation ITURF.1244.
NOTE 1 - Acronyms and terminology used in this Recommendation is given in Table 1.
Table 1
Acronyms and terms used in this Recommendation AFCAGA
AP
ARA
ARP
ATM
BPSK
BRAN
CCK
CSMA/CA
DCS
DFS
DHCP
DQPSK
DS
ETSI
FDD
FDMA
FFT
FH
FSK
FWA
GI
GMSK
HBR
IFFT
IF
IP
ISI
LBR
LMS
LSI
MAC
OFDM
PDU
PPP
PSK
QAM
QPSK
RF
RLS
SOHO
SSMA
TCP
TDMA
TDD
TPC
WATM
WLAN / Automatic Frequency Control
Automatic Gain Amp
Access Point
Apple Remote Access
Authentication Request Packet
Asynchronous Transfer Mode
Binary Phase Shift Keying
Broadband Radio Networks
Complementary Code Keying
Carrier Sensing Multiple Access with Collision Avoidance
Dynamic Channel Selection
Dynamic Frequency Selection
Dynamic Host Configuration Protocol
Differential Quaternary Phase Shift Keying
Direct Sequence
European Telecommunications Standards Institute
Frequency Division Duplex
Frequency Division Multiple Access
Fast Fourier Transform
Frequency Hopping
Frequency Shift Keying
Fixed Wireless Access
Guard Interval
Gaussian Minimum Shift Keying
High Bit Rate HiperLAN 1 for data period only
Inverse Fast Fourier Transform
Intermediate frequency
Internet Protocol
Inter Symbol Interference
Low Bit Rate HiperLAN 1 for signalling period only
Least Mean Square
Large Scale Integrated circuits
Medium achine Access Control
Orthogonal Frequency Division Multiplexing
Protocol Data Units
Point-to-Point Protocol
Phase Shift Keying
Quadrature Amplitude Modulation
Quaternary Phase Shift Keying
Radio Frequency
Recursive Least Squares
Small Office Home Office
Spread Spectrum Multiple Access
Transmission Control Protocol
Time Division Multiple Access
Time Division Duplex
Transmit Power Control
Wireless Asynchronous Transfer Mode
Wireless Local Area Network
Access method
Bit rate
Channelization
Frequency band
Modulation
Tx power / Scheme used to provide multiple access to a channel
The rate of transfer of bit information from one network device to another
Bandwidth of each channel and number of channels that can be contained in the RF Bandwidth allocation
Nominal operating spectrum of application
The method used to put digital information on an RF carrier
(Transmitter power) - RF power in watts produced by the transmitter.
TABLE 2
Methods of multiple access and modulation techniques
Frequency band / Multiple access / Modulation techniqueUHF / CSMA/CA
FDMA
TDMA
SSMA-DS
SSMA-FH / CCK (Complementary Code Keying)
SHF / CSMA/CA
FDMA
TDMA-FDD
TDMA-TDD
TDMA/EY-NPMA / GMSK/FSK
BPSK-OFDM
QPSK-OFDM
8-PSK-OFDM
16-QAM-OFDM
64-QAM-OFDM
Table 3
Technical parameters for broadband RLAN applications
NetworkRLAN standard / IEEEProjectStd 802.11b / IEEE ProjectStd 802.11a
(NOTE 1) / ETSI BRAN
HIPERLANiperLAN Type 1
ETS 300-652 / ETSI BRAN HiperIPERLAN Type 2
(NOTE 1) (NOTE 2)
Access method / CSMA/CA, SSMA / CSMA/CA / TDMA/EY-NPMA / TDMA/TDD
Modulation / CCK (8 complex chip spreading) / 64 QAM-OFDM
16-QAM-OFDM
QPSK-OFDM
BPSK-OFDM
52 subcarriers
occupied bandwidth
16.6 MHz (see Fig 0.1: Transmit Spectrum mask) / GMSK/FSK / 64-QAM-OFDM
16-QAM-OFDM
QPSK-OFDM
BPSK-OFDM
52 subcarriers
occupied bandwidth
16.6 MHz (see Fig 0.1: Transmit Spectrum mask)
Data rate / 1, 2, 5.5 and 11 Mbit/s / 6, 9, 12, 18, 24, 36, 48 and 54 Mbit/s / 23 Mbit/s (HBR)
1.4 Mbit/s (LBR) / 6, 9, 12, 18, 27, 36, 48 and 54Mbit/s
Frequency band / 2 400 - 2 483.5 MHz / 5 150 - 5 250 MHz
5 725 - 5 825 MHz
5 250 - 5 350 MHz
(NOTE 7 8) / 5 150 to 5 300MHz Limited in some countries to 5 150 to 5250 MHz (NOTE 7 8) / 5 GHz bands are currently under study in CEPT
5 150 – 5 350 MHz
5 470 – 5 725 MHz
(see ERC/DEC/(99)23)
(NOTE 78)
Channelization / 25/30 MHz spacing
3 channels / 20 MHz channel spacing
(8+4) channels / 23.5294 MHz (HBR)
3 channels in 100MHz and 5 channels in 150 MHz
1.4 MHz (LBR) / 20 MHz channel spacing.
194 channels in the 2 bands. 100MHz
Max Tx power / 1 000 mW e.i.r.p.
(NOTE 3)
100 mW e.i.r.p.
(NOTE 45)
10 mW/MHz e.i.r.p. density (NOTE 56) / 5 150 to 5 250 MHz
10 mW/MHz
200 mW e.i.r.p. in 20MHz channel
5 250 - 5 350 MHz
1 W e.i.r.p.
5 725 - 5 825 MHz
4 W e.i.r.p. (NOTE 67)
/ Three different classes of power levels depending on country administration
1 Watt e.i.r.p., 100mW e.i.r.p., 10mW e.i.r.p. (NOTE4) / Current power limits for various bands are under study in CEPT
5 150 – 5 350 MHz
eirp 200 mW max indoor use only.
5 470 – 5 725 MHz
eirp 1W.
Sharing considerations / a)CDMA allows orthogonal spectrum spreading
b)CSMA/CA provides "listen before talk" access etiquette / a)OFDM provides low power spectral density
b)CSMA/CA provides "listen before talk" access etiquette
c)In 5 150 - 5 250 MHz e.i.r.p. density limit should be subject to [PDNR M.[Doc. 8A9B/ TEMP/22(Rev.1)]]
d) IEEE 802.11h are standardizing DCS and TPC / In 5 150 - 5 250 MHz e.i.r.p. density limit should be subject to PDNR M.[Doc. 8A9B/TEMP/22 (Rev.1)] / a)OFDM provides low power spectral density
b)In 5 150 - 5250 MHz e.i.r.p. density limit should be subject to [PDNR M.[Doc. 8A9B/TEMP/22 (Rev.1)]]
Dynamic Frequency Selection and Transmit Power Control are required.
Minimum
Receiver Sensitivity / 6 Mb/s: -82 dBm
54 Mb/s: -65 dBm
10% PER 1000 Byte PDU / 6 Mb/s: -85 dBm
54 Mb/s: -68 dBm
10% PER 54 Byte PDU
Figure 0.1 Transmit Spectrum Mask
NOTE 1 - Common parameters for the physical layer have been published in the IEEE Std are now under study betweenIEEE 802.11a-1999 (Supplement to IEEE Std 802 11-1999) and ETSI BRANHIPERLAN Type 2;2 ETSI TS 101 475 Physical (PHY) layer .NOTE 2 - WATM (Wireless ATM) and advanced IP with QoS (Ipv^, RSVP) are intended for use over ETSI BRAN HIPERLAN 2 physical transport. HIPERLAN Type 2 supports cell based (ATM) and packet based (IP) core networks.
NOTE 3 - This requirement refers to FCC 15.247 in the United States.
NOTE 4 - Some restrictions on max output power are under study in the band 5 150 - 5 250 MHz within CEPT.
NOTE 45 - This requirement refers to EUROPE ETS 300-328.
NOTE 65 - This requirement refers to JAPAN MPT ordinance for Regulating Radio Equipment, Article 49-20.
NOTE 76- All values from FCC amendment of the Commission's Rules to Docket No. 96-102 provide for operation of unlicensed NII (RM-8648) devices in the 5 GHz frequency range (RM-865) FCC Part 15 Subpart E - Unlicensed National Information Infrastructure Devices
NOTE 87 - For the band 5 150 to 5 250 MHz, Radio Regulations No. S5.447 applies.
ANNEX 1
General guidance for broadband RLAN system design
1Introduction
Emerging broadband RLAN standards will allow compatibility with wired LANs such as IEEE 802.3, 10BASE-T, 100BASE-T and 51.2 Mbit/s ATM at comparable data rates.Some broadband RLANs have been developed to be compatible with current wired LANs and are intended to function as an wireless extension of wired LANs using TCP/IP and ATM protocols. This will allow operation without the "bottle neck" that occurs with current wireless LANs. Recent bandwidth allocations by some administrations will promote development of broadband RLANs. This will allow applications such as Audio/Video Streaming to be supported with high QoS.
A feature provided by broadband RLANs not provided by wired LANs is portability. New laptop and palmtop computers are very portable and have the ability when connected to a wired LAN to provide interactive services. However, when they are connected to wired LANs one loses the portability feature. Broadband RLANs allow portable computing devices to remain portable and operate at maximum potential.
Private on-premise, computer networks are not covered by traditional definitions of fixed and mobile wireless access and should be considered. The nomadic user of the future will no longer be bound to a desk. Instead, they will be able to carry their computing devices with them and maintain contact with the wired LAN in a facility.
1.1Characteristics of broadband RLANs
Speeds of notebook computers and hand held computing devices are increasing steadily. Many of these devices are able to provide interactive communications between users on a wired network but sacrifice portability when connected. Multimedia applications and services require broadband communications facilities not only for wired terminals but also for portable and personal communications devices. Wired local area network standards, i.e. IEEE 802.3ab 1000BASE-T, are in development that will be able to transport high rate, multimedia applications. To maintain portability, future wireless LANs will need to transport higher data rates. Broadband RLANs are generally defined as those that can provide data throughput greater than 210 Mbit/s.
1.12Mobility
Broadband RLANs may be either pseudo fixed as in the case of a desktop computer that may be transported from place to place or portable as in the case of a laptop or palm top devices working on batteries. Relative velocity between devices remains low. In warehousing applications, RLANs may be used to maintain contact with lift trucks at speeds of up to 6 metres per second. RLAN devices are generally not designed to be used at automotive or higher speeds.
1.23Operational environment and considerations of interface
Broadband RLANs are predominantly deployed inside buildings, in offices, factories, warehouses, etc. For RLAN devices to be deployed inside buildings, emissions will be attenuated by the structure.
RLANs utilize low power levels because of the short distance nature of inside building operation. Power spectral density requirements are based on a basic service area of a single RLAN defined by a circle with a radius from 10 to 50 metres. When larger networks are required, RLANS may be logically concatenated via bridge or router function to form larger networks without increasing their composite power spectral density.
One of the most useful RLAN features is the connection of mobile computer users to their own LAN network without wires. In other words, a mobile user can be connected to itstheir own LAN subnetwork anywhere within the RLAN service area. The service area may expand to other locations under different LAN subnetworks, enhancing the mobile user's convenience.
Annex 2 of this document describes several remote access network techniques to enable the RLAN service area to extend to other RLANs under different subnetworks. Among these techniques, the mobile VLAN technique is a most promising enhancement.
To achieve the coverage areas specified above, it is assumed that RLANs require a peak power spectral density of approximately 12.5 mW/MHz in the 5 GHz operating frequency range. For data transmission, some standards use higher power spectral density for initialization and control the transmit power according to evaluation of the RF link quality. This technique is referred to as transmit power control (TPC).. The required power spectral density is proportional to the square of the operating frequency. The large scale, average power spectral density will be substantially lower than the peak value. RLAN devices share the frequency spectrum on a time basis. Activity ratio will vary depending on the usage, in terms of application and period of the day.
Broadband RLAN devices are normally deployed in high density configurations and may use an etiquette such as "listen before talk" and dynamic channel assignment selection (referred to here as dynamic frequency selection, DFS, transmit power control to facilitate spectrum sharing between devices.
1.34System architecture
Broadband RLANs are nearly always point-to-multipoint architecture. Point-to-multipoint applications commonly use omnidirectional, down looking antennas. The multipoint architecture employs two system configurations:
1.4.1Point-to-multipoint centralized system (multiple devices connecting to a central device or access point (AP) via a radio interface).
1.4.2Point-to-multipoint non-centralized system (multiple devices communicating in a small area on an ad hoc basis).
1.4.3RLAN technology is sometimes used Occasionally, fixed point-to-point devices are to implementedfixed point-to-point links between buildings in a campus environment. Point-to-point systems commonly use directional antennas that allow greater distance between devices with a narrow lobe angle. This allows band sharing via channel reuse with a minimum of interference with other applications.
1.5 Spectrum re-use
RLANs are generally intended to operate in unlicensed or license-exempt spectrum and must allow adjacent uncoordinated networks to co-exist whilst providing high service quality to users. In the 5 GHz bands, sharing with primary services must also be possible. Whilst multiple access techniques might allow a single frequency channel to be used by several nodes, support of many users with high service quality requires enough channels are available to ensure access to the radio resource is not limited through queing etc. One technique that achieves a flexible sharing of the radio resource is Dynamic Frequency Selection, DFS, which is employed in the ETSI Hiperlan2 standard and in development by IEEE 802.11.
In DFS all radio resources are available at all RLAN nodes. A node (usually a controller node or AP) can temporarily allocate a channel and the selection of a suitable channel is performed based on interference detected or certain quality criteria, e.g. received signal strength , C/I. To obtain relevant quality criteria both the MTs and the AP make regular measurements and report this to the entity making the selection.
DFS can be implemented to ensure that all available frequency channels are utilised with equal probability. This maximises the availablity of a channel to node when it is ready to transmit, and it also ensures that the RF energy is spread uniformly over all channels when integrated over a large number of users. The latter effect facilitates sharing with other services which may be sensitive to the aggregated interference in any particular channel, such as satellite-born receivers.
Transmit Power Control, TPC, is intended to reduce unecessary device power consumption, but also aids in spectrum re-use by reducing the interference range of RLAN nodes.
ANNEX 2
Preferred modulation techniques in broadband wireless LANs
2Introduction
RLAN systems are being marketed all over the world. There are several major standards for broadband wireless LAN systems. ETSI (European Telecommunications Standards Institute) already developed HiperLAN Type-1 standard. Another discussion is currently very active in IEEE802.11, which established a RLAN standard for the 2.4 GHz band. These standards will stimulate economical RLAN equipment. Refer to Table 3 in the main document.
Broadband wireless LAN systems make it possible to move a computer within a certain area such as an office, a factory, and SOHO (Small Office Home Office) with high data rates of more than 20Mbit/s. As a consequence of the great progress in this field, computer users are demanding free movement with bit rates equivalent to those of conventional wired LANs such as 10BASE-T Ethernet. This new demand raises significant issues of a stable physical layer for broadband radio transmission. There are two major candidates for this purpose: the one is an equalization scheme and the other is a multicarrier scheme.
This document presents features of the modulation techniques used in the standards listed in Table 3 in the main document. presents features of both schemes and comparison between them. A stable high bit rate, physical layer, which employs DQPSK-OFDM (Orthogonal Frequency Division Multiplexing) with convolutional encoding, is recommended.
2.1Physical layer to realize high bit rate and stable wireless networks
The broadband radio channel is known to be frequency selective, causing Inter Symbol Interference (ISI) in the time domain and deep notches in the frequency domain. To realize a high speed, wireless access system under frequency selective fading channels, a possible method is to shorten the symbol period. A second way is to use bandwidth efficiently by multi-level modulation. The third way is to employ multicarrier modulation. The first and second solutions show serious drawbacks in multipath environments. In the first solution, as the symbol period decreases, ISI becomes a severe problem. Therefore, equalization techniques will be necessary. The second solution reduces the symbol distance in the signal space and hence the margin for thermal noise or interference is decreased, leading to intolerable performance degradation for high speed, wireless access systems. The third solution, the multicarrier method, is to increase the symbol period in order to compensate for ISI resulting from multi-path propagation. As promising methods for multipath countermeasures, the first solution of single carrier with equalizer and the third solution using multicarrier methods (OFDM) are discussed below.